Association between the introduction of a national targeted intervention program and the incidence of surgical site infections in Swiss acute care hospitals.

BACKGROUND: In Switzerland, the national surgical site infection (SSI) surveillance program showed a modest decrease in SSI rates for different procedures over the last decade. The study aimed to determine whether a multimodal, targeted intervention program in addition to existing SSI surveillance is associated with decreased SSI rates in the participating hospitals. METHODS: Prospective multicenter pre- and postintervention study conducted in eight Swiss acute care hospitals between 2013 and 2020. All consecutive patients > 18 years undergoing cardiac, colon, or hip/knee replacement surgery were included. The follow-up period was 30 days and one year for implant-related surgery. Patients with at least one follow-up were included. The intervention was to optimize three elements of preoperative management: (i) hair removal; (ii) skin disinfection; and (iii) perioperative antimicrobial prophylaxis. We compared SSI incidence rates (main outcome measure) pre- and postintervention (three years each) adjusted for potential confounders. Poisson generalized linear mixed models fitted to quarter-yearly confirmed SSIs and adjusted for baseline differences between hospitals and procedures. Adherence was routinely monitored through on-site visits. RESULTS: A total of 10 151 patients were included, with a similar median age pre- and postintervention (69.6 and IQR 60.9, 76.8 years, vs 69.5 and IQR 60.4, 76.8 years, respectively; P = 0.55) and similar proportions of females (44.8% vs. 46.1%, respectively; P = 0.227). Preintervention, 309 SSIs occurred in 5 489 patients (5.6%), compared to 226 infections in 4 662 cases (4.8%, P = 0.09) postintervention. The adjusted incidence rate ratio (aIRR) for overall SSI after intervention implementation was 0.81 (95% CI, 0.68 to 0.96, P = 0.02). For cardiac surgery (n = 2 927), the aIRR of SSI was 0.48 (95% CI, 0.32 to 0.72, P < 0.001). For hip/knee replacement surgery (n = 4 522), the aIRR was 0.88 (95% CI, 0.52 to 1.48, P = 0.63), and for colon surgery (n = 2 702), the aIRR was 0.92 (95% CI, 0.75 to 1.14, P = 0.49). CONCLUSIONS: The SSI intervention bundle was associated with a statistically significant decrease in SSI cases. A significant association was observed for cardiac surgery. Adding a specific intervention program can add value compared to routine surveillance only. Further prevention modules might be necessary for colon and orthopedic surgery.

Handrub dispensers per acute care hospital bed: a study to develop a new minimum standard.

BACKGROUND: Accessibility to alcohol-based handrub (ABHR) dispenser is crucial to improve compliance to hand hygiene (HH), being offered as wall-mounted dispensers (ABHR-Ds), and/or pocket bottles. Nevertheless, information on the distribution and density of ABHR-Ds and their impact on HH have hardly been studied. Institutions such as the World Health Organisation or the Centers for Disease Control and Prevention do not provide guidance. The Robert-Koch-Institute (RKI) from Germany recommends an overall density of > 0.5 dispensers per patient bed. We aimed to investigate current conditions in hospitals to develop a standard on the minimal number of ABHR-D. METHODS: Between 07 and 09/2019, we applied a questionnaire to 178 hospitals participating in the Swissnoso National Surveillance Network to evaluate number and location of ABHR-Ds per bed in acute care hospitals, and compared the data with consumption and compliance with HH. RESULTS: 110 of the 178 (62%) hospitals provided data representing approximately 20,000 hospital beds. 83% hospitals provided information on both the total number of ABHR-Ds and patient beds, with a mean of 2.4 ABHR-Ds per bed (range, 0.4-22.1). While most hospitals (84%) had dispensers located at the room entrance, 47% reported also locations near or at the bed. Additionally, pocket-sized dispensers (100 mL) are available in 97% of hospitals. CONCLUSIONS: Swiss hospitals provide 2.4 dispensers per bed, much more than governmental recommendation. The first study on the number of ABHR-Ds in hospitals may help to define a minimal standard for national and international recommendations.

Systematic screening on admission for SARS-CoV-2 to detect asymptomatic infections.

The proportion of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains elusive and the potential benefit of systematic screening during the SARS-CoV-2-pandemic is controversial. We investigated the proportion of asymptomatic inpatients who were identified by systematic screening for SARS-CoV-2 upon hospital admission. Our analysis revealed that systematic screening of asymptomatic inpatients detects a low total number of SARS-CoV-2 infections (0.1%), questioning the cost-benefit ratio of this intervention. Even when the population-wide prevalence was low, the proportion of asymptomatic carriers remained stable, supporting the need for universal infection prevention and control strategies to avoid onward transmission by undetected SARS-CoV-2-carriers during the pandemic.

Antimicrobial Prophylaxis for Postoperative Urinary Tract Infections in Transurethral Resection of Bladder Tumors: A Systematic Review and Meta-Analysis.

PURPOSE: The administration of antimicrobial prophylaxis for postoperative urinary tract infections following transurethral resection of bladder tumors is controversial. We aimed to systematically review evidence on the potential effect of antimicrobial prophylaxis on postoperative urinary tract infections and asymptomatic bacteriuria. MATERIALS AND METHODS: We conducted a systematic search in Embase®, Medline® and the Cochrane Central Register of Controlled Trials. Randomized controlled trials and nonrandomized controlled trials assessing the effect of any form of antimicrobial prophylaxis in patients with transurethral resection of bladder tumors on postoperative urinary tract infections or asymptomatic bacteriuria were included. Risk of bias was assessed using RoB 2.0 or the Newcastle-Ottawa Scale. Fixed and random effects meta-analyses were conducted. As a potential basis for a scoping review, we exploratorily searched Medline for risk factors for urinary tract infections after transurethral resection of bladder tumors. The protocol was registered on PROSPERO (CRD42019131733). RESULTS: Of 986 screened publications, 7 studies with 1,725 participants were included; the reported effect sizes varied considerably. We found no significant effect of antimicrobial prophylaxis on urinary tract infections: the pooled odds ratio of the random effects model was 1.55 (95% CI 0.73-3.31). The random effects meta-analysis examining the effect of antimicrobial prophylaxis on asymptomatic bacteriuria showed an OR of 0.43 (0.18-1.04). Risk of bias was moderate. Our exploratory search identified 3 studies reporting age, preoperative pelvic radiation, preoperative hospital stay, duration of operation, tumor size, preoperative asymptomatic bacteriuria and pyuria as risk factors for urinary tract infections following transurethral resection of bladder tumors. CONCLUSIONS: We observed insufficient evidence supporting routine antimicrobial prophylaxis in patients undergoing transurethral resection of bladder tumors for the prevention of postoperative urinary tract infections; our findings may inform harmonization of international guidelines.

Are three antiseptic paints needed for safe preparation of the surgical field? A prospective cohort study with 239 patients.

BACKGROUND: Preoperative skin antisepsis is an essential component of safe surgery. However, it is unclear how many antiseptic paints are needed to eliminate bacteria prior to incision. This study compared microbial skin counts after two and three antiseptic paints. METHODS: We conducted a prospective cohort study in non-emergency patients receiving a cardiac/abdominal surgery with standardized, preoperative skin antisepsis consisting of an alcoholic compound and either povidone iodine (PI) or chlorhexidine (CHX). We obtained three skin swabs from the participant's thorax/abdomen using a sterile template with a 25 cm2 window: After collection of the first swab prior to skin antisepsis, and once the second and third application of PI/CHX had dried out, we obtained a second and third swab, respectively. Our primary outcome was the reduction in microbial skin counts after two and three paints of PI/CHX. RESULTS: Among the 239 enrolled patients, there was no significant difference in the reduction of mean square root-transformed microbial skin counts with three versus two paints (P = 0.2). But distributions of colony forming units (CFUs) decreased from paint 2 to 3 in a predefined analysis (P = 0.002). There was strong evidence of an increased proportion of patients with zero CFU after paint 3 versus paint 2 (P = 0.003). We did not identify risk factors for insufficient reduction of microbial skin counts after two paints, defined as the detection of > 5 CFUs and/or ≥ 1 pathogens. CONCLUSIONS: In non-emergency surgical patients, three antiseptic paints may be superior to two paints in reducing microbial skin colonization prior to surgery.

Parvimonas micra as a rare cause of spondylodiscitis - case series from a single centre.

BACKGROUND: The anaerobe Parvimonas micra is usually recovered as part of the normal flora or in polymicrobial infections of odontogenic or gastrointestinal origin. P. micra has rarely been described as the causative organism of pyogenic spondylodiscitis. Here we report multiple cases of spondylodiscitis caused by this organism and compare their clinical features with the published literature. METHODS: We performed a retrospective review of all institutional cases with P. micra spondylodiscitis between 01 June 2012 and 31 May 2019. For comparison, the literature was searched for studies reporting vertebral infections with P. micra in adult patients. RESULTS: Over 7 years, six cases were identified: one with a polymicrobial infection (with P. micra and Fusobacterium nucleatum) and five with P. micra as the only pathogen isolated. The six patients with P. micra infections were between 63 and 82 years old (median 72 years) and presented with persistent lower back pain. Common findings were infection of the lumbar spine region (in 6/6 cases) and recent dental inflammation (4/6 cases). 3/6 patients had previously undergone decompressive spinal surgery due to spinal stenosis (2 to 11 years before). In 4/6 cases the organism was detected in blood cultures drawn at admission. Treatment consisted of antibiotics for all patients and additional decompressive surgery due to abscess formation in half the cases. Outcomes were mostly favourable, but persistent pain was a common complaint after resolution of infection. CONCLUSIONS: P. micra is a rare cause of spondylodiscitis. Nevertheless, recent dental procedures with subsequent back pain should lead to the consideration of possible anaerobic causes of spondylodiscitis. Heightened awareness of this pathogen and improvements in diagnostic methods might lead to higher detection rates.

Antibiotic prophylaxis in transurethral resection of bladder tumours: study protocol for a systematic review and meta-analysis.

BACKGROUND: The necessity of antibiotic prophylaxis for postoperative urinary tract infections (UTIs) after transurethral resection of bladder tumours is controversial. This potentially leads to the overuse of antibiotic prophylaxis and rising antimicrobial resistance rates. The objective of this systematic review and meta-analysis is to compare the impact of different antimicrobial prophylaxis schemes versus placebo on the prevention of postoperative UTI and asymptomatic bacteriuria. METHODS: We designed and registered a study protocol for a systematic review and meta-analysis of randomized controlled trials and non-randomized (e.g. cohort, case-control) studies examining any form of antibiotic prophylaxis in patients with transurethral resection of bladder tumours. Literature searches will be conducted in several electronic databases (from inception onwards), including MEDLINE (Ovid), EMBASE (Ovid), and the Cochrane Central Register of Controlled Trials (CENTRAL). Grey literature will be identified through searching conference abstracts. The primary outcome will be postoperative urinary tract infections. The secondary outcome will be asymptomatic bacteriuria. Two reviewers will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The study methodological quality (or bias) will be appraised using appropriate tools (e.g. Risk of Bias 2.0 tool and Newcastle-Ottawa Scale). If feasible, we will conduct random-effects meta-analysis of outcome data. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g. study design, publication year, the setting of the study, and antibiotics regimen). We will also search, identify, and discuss potential risk factors for urinary tract infections following transurethral resection of bladder tumours. This may serve as basis for a scoping review. DISCUSSION: In times of rising antimicrobial resistance rates, sound evidence on the necessity of antibiotic prophylaxis is essential for implementation into guideline recommendations and for decision-making in clinical practice. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42019131733.

High incidence of urinary tract infections after photoselective laser vaporisation of the prostate: a risk factor analysis of 665 patients.

PURPOSE: Although photoselective laser vaporisation of the prostate (PVP) is a recognised alternative to transurethral resection in treating benign prostatic obstruction, there is limited data on the incidence and determinants of postoperative urinary tract infections (UTI). We assessed patients subjected to PVP, evaluating incidence and potential determinants of postoperative UTIs. MATERIALS AND METHODS: Consecutive patients undergoing PVP between April 2010 and August 2018 were candidates for this retrospective cohort study. The primary outcome measure was microbiologically confirmed postoperative UTI. We fitted uni- and multi-variable Cox models to identify potential risk factors. RESULTS: Among the 665 included patients, 20% developed postoperative UTIs. The overall incidence rate per 100 patient-days was 0.65 (95% confidence interval [CI] 0.55-0.77). Risk factors for postoperative UTIs were end-stage renal failure (adjusted hazard ratio [aHR] = 14.10, 95% CI 2.08-64.58; p = 0.001) and presence of at least one of the following factors in the 3 months preceding PVP: (i) placement of urinary catheter, (ii) bacteriuria, (iii) UTI, or (iv) antimicrobial treatment (composite aHR = 1.99, 95% CI 1.22-3.24; p < 0.001). There was no apparent association between choice or duration of antimicrobial prophylaxis and incident UTIs. CONCLUSIONS: Our analysis revealed a high incidence of UTIs after PVP and served to identify certain preoperative risk factors. Neither the choice of antimicrobial regimen nor its duration affected the incidence of UTIs. Prolonged antimicrobials proved to be disproportionately high, warranting further scrutiny in randomised controlled trials.

Contribution of specific pathogens to bloodstream infection mortality in neutropenic patients with hematologic malignancies: Results from a multicentric surveillance cohort study.

Bloodstream infection (BSI) remains a serious complication in patients with hematologic malignancies and neutropenia. The risk factors for mortality after BSI and the contributions of BSI pathogens to mortality remain incompletely understood. We evaluated first BSI among adult neutropenic patients undergoing high-dose chemotherapy for hematologic malignancies in the setting of (a) an early disease stage of autologous (auto-HSCT) or allogeneic (allo-HSCT) hematopoietic stem cell transplantation or (b) for acute leukemia. Risk factors for intensive care admission and all-cause mortality were analyzed by multivariable logistic regression 7 and 30 days after onset of the first BSI in the first neutropenic episode. Between 2002 and 2015, 9080 patients met the study inclusion criteria, and 1424 (16%) developed BSIs, most of them during the first week of neutropenia. Mortality during neutropenia within 7 days and 30 days after BSI onset was 2.5% and 5.1%, respectively, and differed considerably between BSI pathogens. Both 7-day and 30-day mortalities were highest for Pseudomonas aeruginosa BSI (16.7% and 26.7%, respectively) and lowest for BSI due to coagulase-negative Staphylococcus spp. (CoNS) and Streptococcus spp. BSI pathogens were independently associated with 7-day mortality included P aeruginosa, Klebsiella spp., Enterobacter spp., Serratia spp., and enterococci. Only gram-negative BSI and candidemia were associated with admission to intensive care within 7 days after BSI onset. BSI caused by P aeruginosa continues to carry a particularly poor prognosis in neutropenic patients. The unexpected association between enterococcal BSI and increased mortality needs further study.

Early versus late onset bloodstream infection during neutropenia after high-dose chemotherapy for hematologic malignancy.

PURPOSE: The length of neutropenia has a significant impact on the incidence of bloodstream infection (BSI) in cancer patients, but limited information is available about the pathogen distribution in late BSI. METHODS: Between 2002 and 2014, BSI episodes in patients with neutropenia receiving chemotherapy for hematologic malignancies were prospectively identified by multicenter, active surveillance in Germany, Switzerland and Austria. The incidence of first BSI episodes, their microbiology and time to BSI onset during the first episode of neutropenia of 15,988 patients are described. RESULTS: The incidence rate of BSI episodes was 14.7, 8.7, and 4.7 per 1000 patient-days in the first, second, and third week of neutropenia, respectively. BSI developed after a median of 5 days of neutropenia (interquartile range [IQR] 3-10 days). The medium duration of neutropenia to BSI onset was 4 days in Escherichia coli (IQR 3-7 days), Klebsiella spp. (2-8 days), and Staphylococcus aureus (3-6 days). In contrast, BSI due to Enterococcus faecium occurred after a median of 9 days (IQR 6-14 days; p < 0.001 vs. other BSI). Late onset of BSI (occurring after the first week of neutropenia) was also observed for Stenotrophomonas maltophilia (12 days, IQR 7-17 days; p < 0.001), and non-albicans Candida spp. (13 days, IQR 8-19 days; p < 0.001). CONCLUSIONS: Over the course of neutropenia, the proportion of difficult to treat pathogens such as E. faecium, S. maltophilia, and Candida spp. increased. Among other factors, prior duration of neutropenia may help to guide empiric antimicrobial treatment in febrile neutropenia.

Cardiovascular daytime varying effect in cardiac surgery on surgical site infections and 1-year mortality: A prospective cohort study with 22,305 patients.

Afternoon aortic valve replacement surgery may provide perioperative myocardial protection and improve patient outcomes compared with morning surgery. The results of our large observational study based on Swiss cardiac surgical site infection surveillance data suggest that the current evidence is insufficient to generally promote afternoon cardiac surgeries.

Single-dose versus 3-day cotrimoxazole prophylaxis in transurethral resection or greenlight laser vaporisation of the prostate: study protocol for a multicentre randomised placebo controlled non-inferiority trial (CITrUS trial).

BACKGROUND: Transurethral resection of the prostate (TURP) and Greenlight laser vaporisation (GL) of the prostate are frequently performed urological procedures. For TURP, a single-dose antimicrobial prophylaxis (AP) is recommended to reduce postoperative urinary tract infections. So far, no international recommendations for AP have been established for GL. In a survey-based study in Switzerland, Germany and Austria, urologists reported routinely extending AP primarily for 3 days after both interventions. We therefore aim to determine whether single-dose AP with cotrimoxazole is non-inferior to 3-day AP with cotrimoxazole in patients undergoing TURP or GL of the prostate. METHODS/DESIGN: We will conduct an investigator-initiated, multicentre, randomised controlled trial. We plan to assess the non-inferiority of single-dose AP compared to 3-day AP. The primary outcome is the occurrence of clinically diagnosed symptomatic urinary tract infections which are treated with antimicrobial agents within 30 days after randomisation. The vast majority of collected outcomes will be assessed from routinely collected data. The sample size was estimated to be able to show the non-inferiority of single-dose AP compared to 3-day AP with at least 80% power (1 - ß = 0.8) at a significance level of α = 5%, applying a 1:1 randomisation scheme. The non-inferiority margin was determined in order to preserve 70% of the effect of usual care on the primary outcome. For an assumed event rate of 9% in both treatment arms, this resulted in a non-inferiority margin of 4.4% (i.e. 13.4% to 9%). To prove non-inferiority, a total of 1574 patients should be recruited, in order to have 1416 evaluable patients. The study is supported by the Swiss National Science Foundation. DISCUSSION: For AP in TURP and GL, there is a large gap between usual clinical practice and evidence-based guidelines. If single-dose AP proves non-inferior to prolonged AP, our study findings may help to reduce the duration of AP in daily routine-potentially reducing the risk of emerging resistance and complications related to AP. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03633643 . Registered 16 August 2018.

Antimicrobial prophylaxis and the prevention of surgical site infection in cardiac surgery: an analysis of 21 007 patients in Switzerland†.

OBJECTIVES: Our goal was to determine the optimal timing and choice of surgical antimicrobial prophylaxis (SAP) in patients having cardiac surgery. METHODS: The setting was the Swiss surgical site infection (SSI) national surveillance system with a follow-up rate of >94%. Participants were patients from 14 hospitals who had cardiac surgery from 2009 to 2017 with clean wounds, SAP with cefuroxime, cefazolin or a vancomycin/cefuroxime combination and timing of SAP within 120 min before the incision. Exposures were SAP timing and agents; the main outcome was the incidence of SSI. We fitted generalized additive and mixed-effects generalized linear models to describe effects predicting SSIs. RESULTS: A total of 21 007 patients were enrolled with an SSI incidence of 5.5%. Administration of SAP within 30 min before the incision was significantly associated with decreased deep/organ space SSI [adjusted odds ratio (OR) 0.73, 95% confidence interval (CI) 0.54-0.98; P = 0.035] compared to administration of SAP 60-120 min before the incision. Cefazolin (adjusted OR 0.64, 95% CI 0.49-0.84; P = 0.001) but not vancomycin/cefuroxime combination (adjusted OR 1.05, 95% CI 0.82-1.34; P = 0.689) was significantly associated with a lower risk of overall SSI compared to cefuroxime alone. Nevertheless, there were no statistically significant differences between the SAP agents and the risk of deep/organ space SSI. CONCLUSIONS: The results from this large prospective study provide substantial arguments that administration of SAP close to the time of the incision is more effective than earlier administration before cardiac surgery, making compliance with SAP administration easier. The choice of SAP appears to play a significant role in the prevention of all SSIs, even after adjusting for confounding variables.

Frequent Door Openings During Cardiac Surgery Are Associated With Increased Risk for Surgical Site Infection: A Prospective Observational Study.

BACKGROUND: Preliminary studies that analyzed surrogate markers have suggested that operating room (OR) door openings may be a risk factor for surgical site infection (SSI). We therefore aimed to estimate the effect of OR door openings on SSI risk in patients undergoing cardiac surgery. METHODS: This prospective, observational study involved consecutive patients undergoing cardiac surgery in 2 prespecified ORs equipped with automatic door-counting devices from June 2016 to October 2017. Occurrence of an SSI within 30 days after cardiac surgery was our primary outcome measure. Respective outcome data were obtained from a national SSI surveillance cohort. We analyzed the relationship between mean OR door opening frequencies and SSI risk by use of uni- and multivariable Cox regression models. RESULTS: A total of 301 594 OR door openings were recorded during the study period, with 87 676 eligible door openings being logged between incision and skin closure. There were 688 patients included in the study, of whom 24 (3.5%) developed an SSI within 30 days after surgery. In uni- and multivariable analysis, an increased mean door opening frequency during cardiac surgery was associated with higher risk for consecutive SSI (adjusted hazard ratio per 5-unit increment, 1.49; 95% confidence interval, 1.11-2.00; P = .008). The observed effect was driven by internal OR door openings toward the clean instrument preparation room. CONCLUSIONS: Frequent door openings during cardiac surgery were independently associated with an increased risk for SSI. This finding warrants further study to establish a potentially causal relationship between OR door openings and the occurrence of SSI.

Costs versus earnings in colon surgery and coronary artery bypass grafting under a prospective payment system: Sufficient financial incentives to reduce surgical site infections?

Based on a surgical site infection (SSI) cohort at an academic center, we showed a median potentially preventable loss per non-SSI case of $17,916 in colon surgery and of $34,741 in coronary artery bypass grafting.

Impact of fluoroquinolone prophylaxis during neutropenia on bloodstream infection: Data from a surveillance program in 8755 patients receiving high-dose chemotherapy for haematologic malignancies between 2009 and 2014.

OBJECTIVES: Antibacterial chemoprophylaxis with fluoroquinolones (FQPx) has been commonly used in cancer patients with neutropenia, but its efficacy has been challenged by the emergence of fluoroquinolone resistance. METHODS: The impact of FQPx on bloodstream infections (BSI) during neutropenia after high-dose chemotherapy for haematologic malignancies was evaluated through a multicenter hospital infection surveillance system for the period 2009-2014. RESULTS: Among 8755 patients (4223 allogeneic [allo-] HSCT, 3602 autologous [auto-] HSCT, 930 high-dose chemotherapy for acute leukemia [HDC]), 5302 (61%) had received FQPx. Administration of FQPx was associated with fewer Gram-negative BSI in the overall study cohort patients (4.6% vs. 7.7%, adjusted subdistribution hazard ratio [aSHR] 0.59, 95%CI 0.50-0.70), in patients with HDC (3.7% vs. 9.2%, adjusted subdistribution hazard ratio [aSHR] 0.40, 95%CI 0.22-0.70) and auto-HSCT patients (4% vs. 9%, aSHR 0.43, 95%CI 0.33-0.56). In HDC patients, FQPx was associated with a marked reduction in all-cause mortality during neutropenia (2.3% vs. 7.8%, aSHR 0.30, 95%CI 0.15-0.58). Patients receiving FQPx had significantly more BSIs due to ESBL-positive Enterobacteriacea (0.8 vs. 0.3%, RR 2.2, 95%CI 1.17-4.26). BSIs by MRSA (n = 5) and VRE (n = 11) were rare in our cohort. CONCLUSIONS: As used in the participating centers, FQPx was associated with reduced Gram-negative BSI and improved survival among HDC patients. Among HSCT patients, the benefits were less clear. If adapted to local resistance patterns and patient characteristics, FQPx still may be useful in the management of patients with haematologic malignancies.

Different Types of Heater-Cooler Units and Their Risk of Transmission of Mycobacterium chimaera During Open-Heart Surgery: Clues From Device Design.

OBJECTIVEWorldwide, Mycobacterium chimaera infections have been linked to contaminated aerosols from heater-cooler units (HCUs) during open-heart surgery. These infections have mainly been associated with the 3T HCU (LivaNova, formerly Sorin). The reasons for this and the risk of transmission from other HCUs have not been systematically assessed.DESIGNProspective observational study.SETTINGUniversity Hospital Basel, Switzerland.METHODSContinuous microbiological surveillance of 3 types of HCUs in use (3T from LivaNova/Sorin and HCU30 and HCU40 from Maquet) was initiated in June 2014, coupled with an epidemiologic workup. Monthly water and air samples were taken. Construction design was analyzed, and exhausted airflow was measured.RESULTS Mycobacterium chimaera grew in 8 of 12 water samples (66%) and 22 of 24 air samples (91%) of initial 3T HCUs in use, and in 2 of 83 water samples (2%) and 0 of 41 (0%) air samples of new replacement 3T HCUs. Moreover, 7 of 12 water samples (58%) and 0 of 4 (0%) air samples from the HCU30 were positive, and 0 of 64 (0%) water samples and 0 of 50 (0%) air samples from the HCU40 were positive. We identified 4 relevant differences in HCU design compared to the 3T: air flow direction, location of cooling ventilators, continuous cooling of the water tank at 4°C, and an electronic alarm in the HCU40 reminding the user of the next disinfection cycle.CONCLUSIONSAll infected patients were associated with a 3T HCU. The individual HCU design may explain the different risk of disseminating M. chimaera into the air of the operating room. These observations can help the construction of improved devices to ensure patient safety during cardiac surgery.Infect Control Hosp Epidemiol 2018;834-840.